C16 pt 2 Flashcards
Intestinal encephalopathy
- sometimes seen in a horse with what condition?
- similar to what?
o Sometimes seen in horses with colitis (excess production of ammonia in the colon?)
o Similar to hepatic encephalopathy
Rectal prolapse
- associated with?
- possible sequelae?
- species specific causes for pig, dog, sheep
o Any species, often associated with straining or increased abdominal pressure (ex.
urinary obstruction, coughing)
o Prolapsed segment becomes edematous and ischemic, may slough
o Sloughing may result in stricture
<><>
- Pig: Zearalenone toxicity from Fusarium spp. mold
- Dog: Brachycephalics predisposed
- sheep: Excessively short docking predisposes
Jejunal hematoma (AKA hemorrhagic bowel syndrome) in cows
- signalment?
- outcome?
- appearance?
o Adult dairy cows, usually causes sudden death but cause is unknown
o Loops of jejunum obstructed by mural hemorrhage, often sharply demarcated
o Affected segments often have mucosal tears that allow blood into the lumen
Duodenitis-proximal jejunitis (AKA proximal enteritis) in the horse
- what is it?
- may lead to?
- what does it cause?
o Upper SI ileus of unknown cause
o Fibrinous enteritis or ulceration of the duodenum, variable extent but spares ileum
o May lead to stricture in chronic cases and may cause peritonitis
o Causes depression, nasogastric reflux, gastric distention and ulceration, occasionally
gastric rupture
Diagnosing GI disease
* Generating a suitable list of differential diagnoses requires you to know:
species and age
Mixed infections are common and often different agents produce the same clinical
disease = ______ diarrhea (until a cause is identified)
undifferentiated
Diagnosing GI disease
* Many agents are transient or cause lesions that are easily obscured by autolysis
- what is it important to examine to make this less of an issue?
o Examining live, untreated animals early in the course of disease is important!
A modified postmortem approach is used in enteric disease to ensure….
…to ensure sections of the gut are fixed in formalin ASAP
o Normally we work from ‘clean to dirty’; in these cases we go straight to the gut
good type of scraping for diagnosing GI diseases
- Some diseases (ex. cryptosporidiosis, coccidia) can be diagnosed from mucosal scrapings
peritoneum
- surface area
- lined by?
- damage and healing?
- how does it heal?
- what growth abnormalities are common?
- Larger surface area than skin, lined by mesothelium
o Easily damaged but heals rapidly via free-floating progenitors
o Healing is even through defect (not edges in)
o Hyperplasia/metaplasia common, can look neoplastic
Peritoneum and retroperitoneum
- involved in what functions?
- what is the retroperitoneum?
- disease in peritoneal cavity usually secondary to what?
- general fluid amount? ante vs post mortem?
- Involved in lubrication, immune surveillance, regulation of inflammation and healing
<><><><> - Retroperitoneum refers to all structures between the peritoneum and dorsal muscles
o Blood vessels, nerves, connective tissue, adipose (good place to see serous atrophy)
<><><><> - Disease is usually secondary to problems with the organs in the peritoneal cavity
<><><><> - Usually little fluid, must differentiate antemortem effusions from postmortem
accumulation (red-tinged, does not clot)
Ascites
- what type of fluid?
- 2 mechanism of development
- what can make it worse?
- Excess fluid, usually modified transudate (watery, clear, straw coloured)
o Two mechanisms of development…
<><><><> - Excess production
o Increased hydrostatic pressures in hepatic and portal circulation
o Most commonly due to fibrosis and congestive heart failure
o Or, leakage of chylous fluid from cisterna chyli
<><> - Insufficient removal
o Obstructed lymphatic drainage to thorax
o Ex. carcinomatosis, space-occupying lesion in thorax
<><><><> - Sodium retention and hypoproteinemia due to liver disease can make ascites worse
Congenital pleuroperitoneal diaphragmatic hernia
- most common in what species?
- issues?
o Most common in dogs
o Herniation of organs into chest can cause respiratory distress, incarceration
Peritoneopericardial diaphragmatic hernia
- usually in what animals?
- how does it happen?
- possible outcomes?
o More common form, usually seen in small animals and may have other defects
o Diaphragm does not fuse or fails to develop properly
o Clinically silent or organ herniation causes cardiac tamponade
Possible consequences of blunt trauma:
Contusions
- Often skin or subcutaneous lesions line up with organ contusions
<><>
Mesenteric/vascular avulsion
- Causes hemorrhage, infarction
<><>
Capsular fracture of solid organs
- Causes hemorrhage, pallor, splenic contraction, splenosis if spleen damaged
<><>
Hollow organ rupture (bladder, gut, uterus, etc)
- Releases contents, can cause peritonitis; in pregnant females, released fetuses will die and cause peritonitis if not removed
<><>
Acquired hernia
- Often diaphragmatic as the diaphragm is weaker than the abdominal wall
why are bladder ruptures hard to find?
- uroperitoneum looks like what? how to differentiate?
- Bladder ruptures are hard to find, as the bladder contracts as urine leaks
o Uroperitoneum looks like ascites – compare creatinine level to serum to confirm
Acquired diaphragmatic hernias
- must confirm what?
- in SA, usually what structure?
- progression and signs?
- in horses, usually what structure and signs?
o Must confirm the hernia developed antemortem (fibrin, hemorrhage, etc)
o In small animals, usually muscular diaphragm
o May be subclinical at first but progresses to respiratory distress, tympany, obstruction,
or abnormal fluid accumulation in the thorax +/- abdomen
o In horses, usually tendinous diaphragm, causes colic rather than respiratory distress
Uroperitoneum
- causes? in neonates?
o Usually due to urolithiasis, in neonates caused by bladder rupture (especially foals)
Digesta in abdomen
- cause? species most commonly affected?
- location
- why can it be hard to find?
- Rectal perforation in horses: cause?
- MUST CONFIRM WHAT? how?
o GI rupture or perforation, most common in horses and cattle
o Can occur anywhere due to foreign bodies, impaction, devitalization
o Site of leakage may be hard to find if there is peritonitis
o Rectal perforation in horses: often iatrogenic, sometimes during parturition
o MUST CONFIRM IF ANTEMORTEM! (hemorrhage, exudate, inflammation)
Pneumoperitoneum
- cause
o Perforated body wall or intestine
most common
Hemoperitoneum
- character?
- spontaneous reasons?
o May be fluid or partly clotted,
traumatic or spontaneous
o Spontaneous: splenic torsion +/-
rupture, GDV, coagulopathy, tumours, ruptured uterus or uterine artery in mares
Abdominal fat necrosis
- associated with what condition in SA?
- appearance?
- In small animals, associated with pancreatitis
o White spots with red borders
Massive abdominal fat necrosis
- signalment
- what happens
- possible issues?
o Poorly understood condition of older, fat, channel island cows
(Jersey, Guernsey)
o Multifocal to coalescing masses of necrotic fat (firm, dry, chalky)
o Often incidental but can cause fatal compression or obstruction of other organs
Steatitis
- what is it?
- related to?
o Peroxidation of adipose throughout the body causes painful inflammation
o Related to high PUFA, low tocopherol diets (vitamin E deficiency in rancid fatty diets)
Peritonitis
- species?
- character?
- Common in large animals, rare in companion animals
o Variety of types of exudate based on cause
o Most cases are secondary but some agents cause primary infectious peritonitis
o May be acute or chronic, local or diffuse, septic or not
Chemical peritonitis
- can be caused by?
o Surgical glove powder (granulomatous), bile, pancreatic enzymes (localized)
Bacterial peritonitis
- causes?
o Direct penetration, GI rupture/devitalization, extension from female reproductive tract
o May also extend from an inflammatory nidus (ex. umbilical abscess)
peritonitis in the horse
- features
- healing
- cause
- type
- Usually diffuse, acute, fatal
- Small omentum and poor healing capacity
- GI rupture most common cause
- Localized possible with castration, mesenteric Streptococcus abscesses
peritonitis in cattle
- features
- immune system
- causes
- sequelae
- neonates causes
- Acute, diffuse, fibrinopurulent progressing to chronic, fibrotic
- Excellent at walling off inflammation and forming abscesses
- Usually due to GI or reproductive tract perforation
- Chronic disease can lead to vagus indigestion
- Hardware disease may involve the pericardium
- In neonates, may extend from umbilical infection
peritonitis in small ruminants
- cause?
Ruptured caseous lymphadenitis lesions or reproductive origin
peritonitis in pigs?
- features
- causes
- Serofibrinous
- Commonly due to Glasser’s disease (polyserositis), also septicemic bacteria (Streptococcus suis, Mycoplasma spp., Trueperella pyogenes)
periotnitis in dogs cause
Usually hollow organ contamination or bacteremia, bacteria vary
peritonitis in cats?
- features
- cause
- Mostly fibrinopurulent
- FIP pyogranulomatous
- Ruptured pyometra, penetrating wounds, Actinomyces spp.
Peritonitis - consequences
- Ileus: supports development of adhesions
- Electrolyte and fluid sequestration in peritoneum and gut
- Absorption of bacterial toxins into lymphatics (may be fatal before gross lesions develop)
<><> - Possible outcomes of peritonitis
1) Resolution
2) Persistence in localized regions (abscesses) 3) Fibrosis
<><> - Fibrin that is not removed by 3-4 days becomes organized into fibrosis
o Effect of adhesions depends on location (subclinical, obstruction, or stenosis) o Ischemia, foreign material, necrosis, and sepsis all promote fibrosis
Mesothelioma
- common?
- malignant?
- species?
- hard to tell from what?
- spread?
- effects?
- appearance?
Mesothelioma: rare, always malignant, most common in cattle and dogs
o Hard to tell apart from reactive mesothelium
o Spread by implantation (not necessarily metastasis), often blocks lymphatics (ascites) o Can affect peritoneum, pleura, and pericardium simultaneously
o Variable gross appearance, can resemble peritonitis or carcinoma
Lipomas (peritoneal)
- common?
- age/species?
- when problematic
- metastatic?
- appearance?
- Lipomas: most common peritoneal interstitial tumour, especially old horses
o Problem if mesenteric lipomas become pedunculated (why?)
o Always benign, often have a friable necrotic core
what cancers can implant on peritoneum?
- primary tumour locations?
- Carcinomas and less commonly sarcomas can implant on peritoneum
o Look for the primary tumour
o Ovarian, biliary, pancreatic, intestinal,
prostatic, renal carcinomas
o Gastric squamous cell carcinoma,
transitional cell carcinoma
o Melanoma in grey horses and occasionally
dogs, etc etc
parasites in the peritoneum
- why?
- which ones?
- Parasites are mostly accidental or on their way somewhere else
o Migrating flukes can cause peritonitis in ruminants
o Setaria spp. nematodes are incidental inhabitants of the ruminant peritoneum
o Larval cestodes and errant Dioctophyme renale are usually incidental
